Has there ever been a 2 car collision at the competitions? I'm not worried about it. The course speeds are so pathetic that if a T-bone was immiment, you could probably stop or go around. There would be something to worry about if a car's throttle sticks open and the brakes fail and the brake overtravel switch fails and the car is in one of the faster gears and the driver panics instead of killing the engine. I'm willing to take that chance.

Yeah, your right. It is about as likely as having a head on colision with anything at almost every competition. I guess someone might go through the same scenario as what you said, and drive a quarter mile off track and hit a curb.

On a more realistic design note, the test tracks of most teams do have more risks than the competition. Ask the teams that have had a crash, better yet, all those who have had a crash should make a post with pics of the damage. If my memory serves me right, a few years back Cornell took a front-on collision with a curb and had significant damage.

I guess, with the amount of poles in the parking lots and the inexperianced drivers, is there a chance of a sliding impact into a pole? I think there is as much a chance of this as there is a front impact.

And my question still stands, has anyone made accomodations in design for the chance of a side impact.

Thanks much,
Bill

Don't go givin people new ideas (rules (obstacles)) for us Bill. But to add a more blood curdling picture to your crushed pelvis scenario, think of what would happen if someone with side pods put the radiators in them. Not only would the crushing blow cause you to scream out in extreme pain, but the boiling water would now be spraying all over you, causing you to get 2nd degree burns. If your lucky, you'll go into shock or pass out from the pain.

ap - worse than that, there was a year (way back whe) our team's frontal impact attenuator WAS the radiator.

We werent so smart back then..

quote:

Originally posted by Jersey Tom:
ap - worse than that, there was a year (way back whe) our team's frontal impact attenuator WAS the radiator.

Wow...

Our team has definately done embarassingly dumb stuff well before my time.

The 07 car has potential to be an unbelieveable step up from our 06 even, which placed 22nd.

Hi all,

I am from The Newcastle of University in Australia, and we made our impact attenuator out of 3 layers of aerolan, each separated by a sheet of aluminium. This was bonded with glue, with wire also used to keep the sandwich together.

We did physical testing at uni with beyond standard results. It then decided (without a vote) to do some destructive testing at the 2006 Australian competition.



Unfortunately the barriers in this area were made from 6 metre lengths of steel guardrail, with a gap in them at the height of every teams impact attenuator. That said, the nose of our car went through the gap and the chassis was effectively the first point of impact. I hope that the event organisers for future events refuse to use this style of barrier where frontal impacts could be expected to occur (ie small skid pans and practice tracks). This style of accident has happened on practice tracks before in Australia, but the other incident was with a water filled plastic barrier, with no chassis damage.

This is no defence of our own design, as every team at this comp in the same scenario would have had their nose go straight through this hole and damage their own chassis. Fortunately with a steel space frame it is easy to cut and weld. Good luck to those of you with a composite chassis.

BIG thanks again to UOA, UOW, RMIT, TAFE & Bill McBride for offering active assistance. We were back and running again for our next event.


Luke Morrow
UN Racing 2004-2007

quote:

ap - worse than that, there was a year (way back whe) our team's frontal impact attenuator WAS the radiator.

We werent so smart back then..

Way way way back when I guess there was a year we did the same and also decided to use the frame tubes themselves as the coolant lines back to the engine ( I imagine there was some sort of rubber line pickup at each end).

We thought about that, use the rollbar is a radiator, untill someone grabbed it to push the car it might work ok.

From what I can tell, the impact attenuator report doesn't actually count for points. Its more of a pass / fail thing. Am I correct in proceeding with this assumption?

Somebody asked for a video of Al honeycomb being tested. You can find one in the bottom of this page:

http://www.unicorn.aau.dk/nyheder/2002811

We tested different types and concluded that honeycomb is perfect if you use the right type. The video shows a pre test experiment with Al comb from a wing of a F16 fighter jet.

And yes, the report is a pass or fail thing.

Hi, My name is Vanessa. I was wondering how you guys test you impact attenuator and wich method do you use to measure deformation and desaceleration. Thanks for your help

quote:

Originally posted by vane:
Hi, My name is Vanessa. I was wondering how you guys test you impact attenuator and wich method do you use to measure deformation and desaceleration. Thanks for your help

After testing a number of ways over a few years, we found that dropping a 300kg 44-gallon drum half full of reinforcement and cement from a forklift onto the test piece proved the most effective results. A quick release was used to drop the drum, and a safety rope was used to prevent the drum from falling over. A high speed camera at 1000 fps and rule in the background were used to record data (knowing time and displacement its easy to get initial velocity, then deformation displacement and then average acceleration is easy).

A sheet aluminium fabrication (riveted or welded) absorbed next to no energy, expanded foam absorbed a small amount of energy while it disintegrated like an imploding building without stopping the drum and an aerolam and sheet aluminium alternating stack ~ 200 mm thick stopped the barrel before it hit the ground, absorbing 108 kJ of energy at a constant 16G.

This is also a great opportunity for a risk assessment! Remember, safety first.

Hi everyone.
I was wondering if any of you knows if we are allowed to present impact attenuator test data from a scale model.

I was actually planing to use only 10 percent of the load determined for the test. Lets say build an impact attenuator scale model 1:10 and drop 30 kilograms instead of 300 kilograms. Obviously using the same drop height.

Thanks in advance

Scale testing is easiest when you scale the energy (in your case the mass) and use a cross section of the same scale (1/10th). The IA length needs to be representative. So, yes you can scale the energy, but don't scale the length. This is because your IAD should also validate that the mass comes to rest in less than the IA length.

I am putting together a little document on IAs for FSAE-A and hope to make this available for all teams at the event, to take into consideration next year. Watch this space.

I think the answer is in Question and Answer # 4 of FAQ # 104, which can be found at:
http://www.formulasae.org/forums/formula/dispatch.cgi/r...%20Test%20Method.doc